Pneumatic brake for goods-trains.



- PATENTED OCT. 24, 1905.

F. J. GHAPSAL & A. L. E.'SAILLOT. PNEUMATIC BRAKE FOR GOODS TRAINS.

APPLICATION TILED DEC. 28. 1904.

w \1 ZZA viz WITNESSES UNITED STATES BATENT OFFICE.

FRANCOIS JULES CHAPSAL AND ALFRED LOUIS EMILE SAILLOT, OF

PARIS, FRANCE.

PNEUMATIC BRAKE FOR GOODS-TRAINS- Specification of Letters Patent,

Patented Oct. 24, 1905.

Application filed December 28, 1904. Serial No. 238,648.

distributer composed of two coordinated parts,

which by acting in combination insure the regulation of the admissionand the discharge -'of the air to and from the brake-cylinders:

mounted upon the same spindle.

The first of these parts, which is termed the distributing-val ve,comprises a special slide controlled by an ordinary piston. By itself itis incapable of insuring either the admission or the discharge of theair to and from the brake-cylinder; but it is constituted for: (a)

- insuring" during the intervals between the h applications-of thebrakes,ontheene-hand, t the simultaneous supply of air from the train-[fpip'eto two diiferent reservoirs, one of which "is termed theregulatingreservoir and regulates the operationof the apparatus, whilethe other is called the braking-reservoir and serves wholly to furnishthe air to the brakecylinder and the placing in communication of the.brake-cylinder and chambers of the second partw'ith the outer air;.'(Z2) immediately I before the beginning and .until the absolute.

termination of each braking to interrupt the vmutual relationshipbetween the two reservoirs, cut of? both of them from the train-pipe,-

and effect the connection of the chambers of the second partalreadyreferred to, as to one of them with the regulating-reservoir and as tothe other with the train-pipe. The second part, termed thebraking-regulator, com prises the ordinary arrangement of threediaphragins or pistons of difiierent diameters Under the influence ofthe dili'erence of pressure between the regulating-reservoir and thetrain-pipe these parts control the ordinary valve regulating theadmission of air from the brakingreservoir into the brake-cylinder andalso a secondivalve regulating the graduated dis- A constructional formof this brake is represented, by way of example, in the accompanyingdrawings, in which Figure 1 shows the brake as a whole as far asconcerns one vehicle, and Figs. .2 and 3 illustrate the action of theslide of the distributing-valve.

The brake represented in Fig. 1 comprises for each vehicle a train-pipeA, the extremity of which terminates in ordinary couplings,

a distributer B, a brake-cylinder C, comprising one or two pistons, anair-reservoir G, and

a braking-reservoir Hm H The distributing-valve B presents, Fig. 1,

two chambers 1 and 2. In the chamber l is j mounted a piston a, one ofthe faces of which I acts as a valve relatively to the chamber- 2;

Its rod carries a slide-valve 6. The chamber 1 1 p is in communication,through a conduit cand the branch E, with aregu lator D, interposed onthe train-pipe A. it also communicatesrby means of a conduit d, with thedistributingvalve face over which the slide 6 moves; a The chamber'2 isin communication with the airreservoir G by means of a pipe e and-withthe' reservoir H by a conduit f, which comprises a branch opening intothe regulators. The conduits d and f both open on the facefor'theslide-valve b, which face also presents four vided with a cavity, whichis hereinafter referred to. incisions are formed at 9' and 70,respectively in the chamber 1 and in the chamher 2, which are likewiseunited in the position of thedistributer-piston represented in thefigure by the intermediary of a non-return valve M, serving tofacilitate the admission of air to the chamber 2.

The braking-regulator is subdivided,,Fig. 1, into four compartments 3 4:5 6 by means of three flexible diaphragms Z, m, and n, which are fixedat their center to one and the same rod 0. The conduit/z, referred toabove, opens into the compartment 3, the conduit 9 opens into thecompartment 6, and that terminating at 2 into the compartment 4..-Thecompart ment 5 is likewise provided with'an' aperture 0, openinginto, the atmosphere,- Thec0mpartmentgi s in communication through thepipe J with the brake-cylinder C. This latter opens externally by meansof an aperture 3 K is a blow-through valve.

l. The train being running, the air of the train-pipe A enters thedistributer B, through the conduit 0 beneath the piston a and maintainsit at the highest point of its stroke. This air flows into the chamber 2on the one hand through the incisions j and hand on the other throughthe non-return valve M, proceedin'd' through the conduit 6, which'isalways open, into the air-reservoir G, and also through the conduit finto the braking-reservoir H. The two reservoirs, united by a non-returnvalve N, are therefore supplied with air at the pressure of thetrain-pipe A. The brake-cylinderU is in constant communication with thechamber 4 of the moderator, which is hereinafter explained, is free fromair when the pis-, tonais at the highest point of its stroke. Underthese conditions the brakes are released. 2. In order to apply thebrakes, the pressure is reduced in the pipe A. When the pressure hasbeen sufliciently reduced, the piston or descends to its lowest point byreason of the diiference of pressure between the air of theregulating-reservoir G and the air in the conduit A. The displacedslide-valve b assumes the position indicated diagramatically in Fig. 3.At this moment the conduit f is obtu'rated; but the air of thebraking-reser voi'r H still passes through the branch of this conduitabove the valve 8. The orificei is obturated, as is also the orifice z.The orifice gr is then open, and the air of the regulating-res: ervoir Gthen reaches the chamber 6 of the moderator, which is of very smallcapacity.. The conduits d and h are in communication through the cavityof the slide-valve'b, and the air of the train-pipe A enters the chamber3v of the moderator. When the conditions are as above set forth, thechamber of the moderator receives the air of the conduit A, which. hasdecreased in pressure, while the chamber 6 fills with air coming fromthe regulatingreservoir G, which has preserved its pressure. The threediaphragms yield toward the left hand, and the arm a lifts the valve .9.The air of the'braking-reservoir H enters the. chamber 4; and thencethrough the pipe J reaches the brake-cylinder G. The brakes aretherefore applied, and as the diaphragm m is larger than the diaphragm Zequilibrium is soon reestablished for a predetermined diminutionofpressure, and when the brakingreservoir has furnishedthe desired.pressure.-.

to the brake-cylinder the diaphragms return to their position ofequilibrium and the valve 8 closes. v

3. If in the course of the stoppage the airsupply of the train-pipeA isreplenished, the equilibrium of the diaphragm is again disturbed, but inthe opposite direction. They' move toward the right hand, and the valve2? is lifted, so that a partial escape takes place of the air of thebrake-cylinder C through the orifice and the application of the brake islessened. The importance of this arrangement will be apparent, as itpermits of beginning the release of the brakes as soon as the train-pipeis recharged, and consequently of reducingthe application of thebrake-shoes at will without modifying the position of the slide-valve ofthe distributer, and therefore without passing through the total-releasestage.

4. In order to completely release the brakes, air is sent into thetrain-pipe A in such a manner as to reestablish the pressure whichpreceded their application. Before this pressure is reached thediaphragms, the equilibrium of which is disturbed by the increase ofpressure in 8, will have opened the air-discharge valve t, the air ofthe brake-cylinder C will have escaped progressively, and the releasewill have taken place gradually. When the initial pressure isreestablished in the conduit A'that is to say, at the moment at whichthe movement of the piston of the distributertakes placethe brake isalready released. The piston a then rises and returns to the positionshown in Fig. 1. The chambers 3, 4, and 6 of the moderator are againplaced in communication with the atmosphere by the slide-valve b, andthe diaphragms are no longer submitted to' the action of the compressedair, whereby their wear is considerably reduced, as it is only duringbraking that they are under pressure. I

It has been shown that the braking-reservoir exerts no influence uponthe operation of the distributer, (which depends only upon theregulating-reservoir.) It may therefore be made of as large a size aspermitted of by practical considerations of mounting, weight, &c.

We claim as our invention- 1. In an air-brake mechanism, a distributercomposed of a distributing-valve in connection with the air-supply, abraking-regulator in connection with the braking-cylinder, reservoirs incommunication with said valve and braking-regulator, and a valvecommunicating between said reservoirs.

2. In an air-brake mechanism, a'distributer composed of adistributing-valve in connection with the air-supply, abraking-regulator in connection with the braking-cylinder, andreservoirs in communication with said valve and said braking-regulator,said distributinglve comprising a cylinder, a piston therein,

a slide-valve on the piston-rod and a separate valve to control theair-supply to one of said reservoirs through said cylinder.

3. In an air-braking mechanism, a distribu- 5 ter composed of adistributing-valve in connection with a braking-regulator, saiddistributing-valve comprising a cylinder, a piston therein and aslidevalve on the pistonrod, and said braking-regulator comprising 10 aplurality of compartments, flexible diaphragms between saidcompartments, and one FRANQOIS JULES CHAPSAL. ALFRED LOUIS EMILESAILLOT.

Witnesses:

CHARLES DOWN, LEON FRANCKINS.

